Under normal circumstances, the body maintains blood sugar in a relatively narrow range through a complex, systematic and precise regulatory mechanism. Once the individual's glucose utilization exceeds the glucose supply for some reason, breaking the stability of the body's blood sugar environment, the plasma glucose concentration begins to decrease, such as: increased insulin or insulin analogs in the blood; insufficient glucose-raising hormones such as cortisol, glucagon, growth hormone and adrenaline; severe lack of sugar intake and (or) absorption; insufficient liver glycogen reserves and (or) breakdown disorders; excessive glucose consumption by tissues and reduced gluconeogenesis, etc. It is generally believed that the standard for hypoglycemia is: plasma glucose concentration is less than 2.8mmol/L (50mg/dl).